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[1/2] drm/i915/glk: Calculate high/low switch count for GLK

Message ID 1494336565-19185-1-git-send-email-madhav.chauhan@intel.com (mailing list archive)
State New, archived
Headers show

Commit Message

Chauhan, Madhav May 9, 2017, 1:29 p.m. UTC
As per BSPEC, high/low switch count to be programmed in
terms of byteclock using exit_zero_count and prep_count.
For Geminilake exit/prep counts are already calculated
in terms of byteclock. This patch calculates high/low
switch count using counts value in byteclock, old calculation
leads to screen flicker/shift issue while resuming from S3/S4.

Signed-off-by: Madhav Chauhan <madhav.chauhan@intel.com>
---
 drivers/gpu/drm/i915/intel_dsi_vbt.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

Comments

Jani Nikula May 15, 2017, 3:48 p.m. UTC | #1
On Tue, 09 May 2017, Madhav Chauhan <madhav.chauhan@intel.com> wrote:
> As per BSPEC, high/low switch count to be programmed in
> terms of byteclock using exit_zero_count and prep_count.
> For Geminilake exit/prep counts are already calculated
> in terms of byteclock. This patch calculates high/low
> switch count using counts value in byteclock, old calculation
> leads to screen flicker/shift issue while resuming from S3/S4.
>
> Signed-off-by: Madhav Chauhan <madhav.chauhan@intel.com>

Pushed this patch to drm-intel-next-queued, thanks for the patch.

BR,
Jani.

> ---
>  drivers/gpu/drm/i915/intel_dsi_vbt.c | 8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/intel_dsi_vbt.c b/drivers/gpu/drm/i915/intel_dsi_vbt.c
> index 0dce779..7158c7c 100644
> --- a/drivers/gpu/drm/i915/intel_dsi_vbt.c
> +++ b/drivers/gpu/drm/i915/intel_dsi_vbt.c
> @@ -694,8 +694,8 @@ bool intel_dsi_vbt_init(struct intel_dsi *intel_dsi, u16 panel_id)
>  						clk_zero_cnt << 8 | prepare_cnt;
>  
>  	/*
> -	 * LP to HS switch count = 4TLPX + PREP_COUNT * 2 + EXIT_ZERO_COUNT * 2
> -	 *					+ 10UI + Extra Byte Count
> +	 * LP to HS switch count = 4TLPX + PREP_COUNT * mul + EXIT_ZERO_COUNT *
> +	 *					mul + 10UI + Extra Byte Count
>  	 *
>  	 * HS to LP switch count = THS-TRAIL + 2TLPX + Extra Byte Count
>  	 * Extra Byte Count is calculated according to number of lanes.
> @@ -708,8 +708,8 @@ bool intel_dsi_vbt_init(struct intel_dsi *intel_dsi, u16 panel_id)
>  	/* B044 */
>  	/* FIXME:
>  	 * The comment above does not match with the code */
> -	lp_to_hs_switch = DIV_ROUND_UP(4 * tlpx_ui + prepare_cnt * 2 +
> -						exit_zero_cnt * 2 + 10, 8);
> +	lp_to_hs_switch = DIV_ROUND_UP(4 * tlpx_ui + prepare_cnt * mul +
> +						exit_zero_cnt * mul + 10, 8);
>  
>  	hs_to_lp_switch = DIV_ROUND_UP(mipi_config->ths_trail + 2 * tlpx_ui, 8);
diff mbox

Patch

diff --git a/drivers/gpu/drm/i915/intel_dsi_vbt.c b/drivers/gpu/drm/i915/intel_dsi_vbt.c
index 0dce779..7158c7c 100644
--- a/drivers/gpu/drm/i915/intel_dsi_vbt.c
+++ b/drivers/gpu/drm/i915/intel_dsi_vbt.c
@@ -694,8 +694,8 @@  bool intel_dsi_vbt_init(struct intel_dsi *intel_dsi, u16 panel_id)
 						clk_zero_cnt << 8 | prepare_cnt;
 
 	/*
-	 * LP to HS switch count = 4TLPX + PREP_COUNT * 2 + EXIT_ZERO_COUNT * 2
-	 *					+ 10UI + Extra Byte Count
+	 * LP to HS switch count = 4TLPX + PREP_COUNT * mul + EXIT_ZERO_COUNT *
+	 *					mul + 10UI + Extra Byte Count
 	 *
 	 * HS to LP switch count = THS-TRAIL + 2TLPX + Extra Byte Count
 	 * Extra Byte Count is calculated according to number of lanes.
@@ -708,8 +708,8 @@  bool intel_dsi_vbt_init(struct intel_dsi *intel_dsi, u16 panel_id)
 	/* B044 */
 	/* FIXME:
 	 * The comment above does not match with the code */
-	lp_to_hs_switch = DIV_ROUND_UP(4 * tlpx_ui + prepare_cnt * 2 +
-						exit_zero_cnt * 2 + 10, 8);
+	lp_to_hs_switch = DIV_ROUND_UP(4 * tlpx_ui + prepare_cnt * mul +
+						exit_zero_cnt * mul + 10, 8);
 
 	hs_to_lp_switch = DIV_ROUND_UP(mipi_config->ths_trail + 2 * tlpx_ui, 8);